Cracks in Your Walls: When to Worry

Cracks in walls and ceilings are common in Australian homes, where reactive clay soils swell and shrink with the weather. Most are harmless, but a few patterns are worth taking seriously.

Cracks that are usually cosmetic

• Fine hairline cracks under about 1 mm wide
• Cracks at the corners of windows and doors that don't grow
• Surface crazing in render or plaster

Cracks worth investigating

• Diagonal cracks wider than 5 mm, especially stepping through brickwork
• Cracks that are growing or opening over weeks and months
• Doors and windows that suddenly jam or won't close
• Sloping or bouncing floors, or gaps opening between walls and ceilings

What an inspection involves

A structural engineer will assess crack width and pattern, check for foundation movement, and consider the soil and drainage around your home. We then provide a clear report explaining the cause and, where needed, a remediation design — from drainage works to underpinning.

Acting early on genuine structural movement almost always costs less than waiting for it to worsen.